1. Technical Field
The invention relates to novel vinyl- and alkoxy-functional organosilicon compounds and to a method for the preparation thereof. More specifically, the invention relates to novel vinyl- and alkoxy-functional organosilicon compounds that contain alkoxy that is highly reactive with the silanol group and to a method for the preparation thereof.
2. Background Information
A large number of alkoxy-functional organosilicon compounds in which alkoxy is bonded to silicon are already known. These are widely used as coupling agents for bonding glass fibers and organic resins and as chain extenders and crosslinkers for silicone polymers and organic polymers. Known examples of these alkoxy-functional organosilicon compounds include monofunctional alkoxysilanes (1 silicon-bonded alkoxy group is present), difunctional alkoxysilanes (2 silicon-bonded alkoxy groups are present), trifunctional alkoxysilanes (3 silicon-bonded alkoxy groups are present), and tetrafunctional alkoxysilanes (4 silicon-bonded alkoxy groups are present). As the number of alkoxy groups in these alkoxysilanes diminishes, the hydrolyzability of the alkoxy groups and their condensation reactivity with the silanol group both decline. As a consequence, the difunctional alkoxysilanes and trifunctional alkoxysilanes are substantially less reactive than the tetrafunctional alkoxysilanes. This has created demand for alkoxy-functional organosilicon compounds that can exhibit the high reactivity of the tetrafunctional alkoxysilanes. The inventors have already proposed an alkoxy-functional organosilicon compound with the following formula for use as a chain extender in U.S. Pat. No. 5,300,612, issued Apr. 5, 1994, to Toshio Saruyama, EQU ((CH.sub.3).sub.3 SiO).sub.2 Si(OCH.sub.3).sub.2
However, the alkoxy groups in this particular alkoxy-functional organosilicon compound do not have a very high condensation reactivity with the silanol group, and this compound is therefore not fully satisfactory for some applications. On the other hand, the vinyl-containing alkoxysilanes, as typified by vinylmethyldimethoxysilane and vinyltrimethoxysilane, contain a different type of alkoxy-functional group in terms of the alkoxysilyl moiety, and one would expect that they could also be used as chain extenders and crosslinkers. Unfortunately, the alkoxy group in these vinyl-containing alkoxysilanes also exhibits an unsatisfactory condensation reactivity with the silanol group.